Best way to model a wavy pattern for CNC milling process?
How's this for a starting point? I took a simple grid mesh and applied edge creases to every other row:



...Scaled it down in one direction and then pulled the edges perpendicular to the creases up and down to build a crude series of parallel waves:



...Then added a subdivision modifier:



There's plenty of room for improvement, but using edges as control points made it relatively simple to sculpt a basic wavy shape without too much hassle.